Electrical equipment such as switchboards, switchgear and others include a plurality of drawout circuit breakers having three pole, four pole, AC, DC configurations and others. The circuit breakers are removeably inserted into associated moveable frames or cradles to establish electrical contact with bus bars, load and line stabs, or similar electrical terminals. When a circuit breaker is removed however, the terminals typically remain energized. This poses a safety hazard since an operator may be injured if the terminals are accidentally touched while servicing the equipment or installing other components near the terminals. Therefore, it is desirable to cover the exposed terminals when a circuit breaker is removed so that the terminals are inaccessible to hinder the possibility of inadvertent contact with the terminals.
A shutter mechanism having moveable shutters is frequently used to cover or expose the terminals. Upon removal of the circuit breaker from a frame, the shutter mechanism causes the shutters to move and close apertures formed in a back wall of the frame so that the bus bar terminals, for example, are covered. Upon insertion of the circuit breaker into the frame, the shutter mechanism causes the shutters to move and expose the apertures to enable contact between the circuit breaker terminals and bus bar terminals. However, conventional shutter mechanisms are difficult to use, expensive to manufacture and are prone to damage.